Biliary System Flashcards
(55 cards)
1
Q
Biliary system components
A
- cystic duct
- GB
- Common bile duct (CBD)
- Common hepatic duct (CHD) (right & left)
2
Q
Cystic duct
A
- branches to GB & drains it
- 2-6 mm in length
- connects neck of GB to CHD to form CBD
3
Q
Spiral Valves of Heister
A
- folds that prevent cystic duct from collapsing & distending
- 2 way street for bile flow
- found in cystic duct
4
Q
Gallbladder appearance
A
- shaped like a pear
- has a neck, body, fundus (all equally important)
- if removed, bile duct can be a little bigger
5
Q
Gallbladder function
A
- used for storage, we can live without it
- behaves like a water balloon
- if scarred too much, won’t work properly
6
Q
Is the GB part of the biliary tree?
A
No but it is part of the biliary tract
7
Q
Common bile duct (CBD)
A
- outside of liver tissue
- should not be under a lot of pressure or dilated
8
Q
Common hepatic duct (CHD)
A
- closest to the liver, within liver tissue
- measure & compare to CBD
- intra hepatic vs. extra hepatic
- right & left hepatic ducts
9
Q
intra hepatic vs. extra hepatic
A
- dilating intra (inside) takes more pressure than extra (outside)
10
Q
right & left hepatic ducts
A
- merge at porta hepatis & becomes CHD
- completes portal triad
11
Q
Pancreatic duct
A
produces digestive enzymes & joins w/ biliary duct
12
Q
Ampulla of Vater
A
- where CBD & main pancreatic duct combine
- opening of duodenum
13
Q
Sphincter of Oddi
A
- muscle that controls the emptying of bile & pancreatic juices through CBD into duodenum
- after the ampulla of vater
- controls pressure differences
14
Q
Infundibulum
A
- part of GB neck nearest to the cystic duct
15
Q
Hartmann’s Pouch
A
- dilation of GB neck b/c it is folded back on itself
- anatomic variation
16
Q
Retrograde
A
backwards
17
Q
Biliary system functions
A
- concentrate & store bile
- transport bile to duodenum
18
Q
Cholecystokinin (CCK)
A
- hormone released by duodenum
- tells biliary system what to do
19
Q
Cholecystokinin (CCK) function
A
- causes GB to contract, then contents are emptied & wall layers thicken
- stimulated once food reaches duodenum
- aids in digestion by breaking down fatty foods & dairy
20
Q
Can you see wall abnormalities when GB is contracted?
A
no, nearly impossible
21
Q
How does cholecystokinin move contents?
A
stimulates GB to contract, sphincter of Oddi opens allowing bile to flow to small intestine
22
Q
Portal triad
A
proper hepatic artery, main portal vein, common hepatic duct (leading to CBD)
23
Q
Porta hepatis
A
- where everything enters the liver
- contains portal triad
24
Q
GB fossa location/size/shape
A
- inf/post to liver border
- pear shaped: neck, body, fundus
- 10 cm in length, 3 cm wall thickness
25
CBD location
- post to duodenum at pancreas posterior
- joins pancreatic duct at ampulla of vater
- sphincter of Oddi = muscle control (Cholecystokinin)
26
How do you find the CBD?
- use main lobar fissure
- follow GB neck from porta hepatis
27
Fundus of GB
- most inferior portion of GB
- usually projects below inferior margin of liver
28
Cystic artery
- supplies GB & biliary tree
- branch of R hepatic artery vessels & ducts course together generally
29
Neck of GB
fixed relationship to main lobar fissure & RPV
30
Fundus of GB
- most inferior portion of the GB
- typically the largest part of GB upon distention
31
What is placed in the body to prevent an obstruction?
ERPC tube
32
What can develop around the gallbladder from pressure?
vericose veins
33
Congenital variants
- variants of anatomy or position
- septate, junction fold, phrygian, duplication
34
Septate GB
- may be partial or complete (double GB)
- splits lumen into several parts, increased chance of obstruction (look for opening in each pocket)
35
Junctional fold
- M/C GB variant (variant of position)
- thick & incomplete
- momentary obstruction
36
2 types of junctional folds
- Hartman's pouch: GB folds back on itself at neck
- Phrygian cap: fold at GB fundus
37
F cap
bubble of gallbladder that can cause obstruction
38
Phrygian
- at fundus
- one variant is position & one is anatomy
39
Duplication of GB
- presence of accessory GB
- Boyden's classification
- 3 different types
40
Boyden's classification
- bilobed, 1 cystic duct, incomplete division
- complete duplication w/ 2 cystic ducts connecting to a single CHD
- complete duplication connecting to a single cystic duct that enters the CHD
41
Types of duplication of GB
- type I (split primordial gallbladders): septated, V-type, Y-type
- type II (accessory gallbladders): H-type (ductular), trabecular
- type III: triple gallbladder
42
Gallbladder imaging
- ideally fasting for at least 6 hours
- anechoic contents w/ echogenic thin wall (<3mm)
- not fasting = won't know if contraction is from eating or a condition
- pear shape in long axis, round in short axis
43
Scanning GB neck
- anchored along portal triad in long axis
- located at porta hepatis w/ main lobar fissure
- elongation of cystic duct should be attempted
- cystic duct isn't always visible
44
What positions may help visualize the cystic duct?
Trendelenburg or right posterior oblique positions
45
Scanning GB fundus
- make sure you have seen the end of it
- moves w/ patient position & gravity
- typically most inferior
46
GB Evaluation
- note pt position & difference of content location
- always look at gallbladder from multiple angles/viewpoints
47
GB wall measurements
- be perpendicular to the wall
- beam needs to hit where you will measure
- try to be adjacent to the liver
- short axis to measure walls (round)
48
Bile duct vessel intersections
- CBD & CHD course along w/ portal veins & hepatic arteries, often anteriorly
- MPV comes from pancreas to liver
49
Bile ducts
- small linear anechoic structures along the portal veins (portal triad)
- CBD courses to the posterior pancreatic head
- enlarged bile ducts generally occur after cholecystectomy & increase in size as the patient ages
50
Why would it be beneficial to have the patient drink water & elevate their head when scanning?
can help visualize the distal CBD & pancreatic head (check that it's the right call first)
51
Scanning bile ducts
-elongating, following to panc. head, note where it ends the liver
- look for portal vein entering the liver, stay on it, should be right near it
- small movements
- don't just slap color on
52
Bile duct wall measurements
- wall shouldn't be more than 4 mm
- once out of liver it shouldn't be more than 6 mm
53
When would it make sense for the bile duct walls to measure longer?
- age allows room for an extra mm per decade once 60 y/o (6mm for 60, 7 mm for 70, etc.)
- removing GB can increase measurement
54
Ideal position for scanning bile duct
- decube position
- start at midline & take a deep breath
- then come up under ribcage & look up to liver
55
Why should you follow the CBD all the way to the end?
to make sure there isn't a stone
